Measurement systems and methods for the noninvasive determination of properties of an object to be examined and/or processes and/or states in an object to be examined by determining the relative phase shift are fundamentally known. For example, reference may be made to European patent application EP 1 447 046 A1 and the German patent applications by the Applicant with the application numbers 10 2006 017 290.6, 10 2006 015 358.8, 10 2006 017 291.4, 10 2006 015 356.1 and 10 2006 015 355.3.
In the field of computer tomography, it is widely known to use phase-contrast media with greatly increased X-ray absorption values in order to be able to better differentiate the contrast between regions with and without incorporated contrast medium.
To improve the image representation, it is thus desirable on the one hand to find media which increase as much as possible the phase shift of the X-radiation passing through the object to be examined in selected regions, in order to achieve a maximally high contrast. Owing to the nature of phase-contrast measurement, at least with non-integrative scanning, phase differences of more than π/2 lead again to lower contrast. Phase shifts which are multiples of π/2 also cannot lead to higher contrasts. Depending on the measurement conditions, this may sometimes entail a reduction of the integratively measured phase shift being induced with the aid of the contrast medium, in order to obtain a phase shift in the increasing range of from 0 to π/2 at the detector.